Renal remodelling: complex interactions between renal and extra-renal cells.

An increasing number of patients suffer from chronic kidney disease (CKD). The progression of CKD is often relentless with the majority of patients reaching end-stage renal disease (ESRD) requiring dialysis. Such a progression depends on complex renal pathology leading to fibrosis. The understanding of the pathophysiology of progressive renal remodelling and scarring has highlighted different pathways based on interactions between intrinsic and extrinsic renal cells. This review discusses the contribution of extrinsic haematopoietic cells to the remodelling that follows a renal insult. It highlights the involvement of bone marrow-derived stem cells in the remodelling of glomerular as well as tubulo-interstitial cells. It also points to the capacity of the kidney cells to dedifferentiate into embryonic phenotypes thus allowing them an active contribution to renal tissue regeneration.